It is known that bicyclic guanidines, such as 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), are chemically active and can be used to catalyze a variety of chemical reactions. An important consideration in the commercial exploitation of bicyclic guanidines as a catalyst (for any reaction) is that bicyclic guanidines be relatively inexpensive to purchase and/or easy to produce.
Published methods for synthesizing bicyclic guanidines, however, are often complicated, such as by using a multiple step and/or time consuming synthesis process. Others use prohibitively expensive and/or hazardous starting materials. Further, many published methods do not produce high yields of the desired products, or produce byproducts, such as aniline, that are difficult to separate from the bicyclic guanidines and may themselves be hazardous. Also, many of these methods produce bicyclic guanidines of different types that may be difficult to separate from one another, and/or produce bicyclic guanidines in forms that are difficult to handle.
There is therefore a need for safe and efficient methods for producing bicyclic guanidines.